1. Field of the Invention
The present invention relates generally to a torque wrench, and more particularly to a torque wrench capable of correcting torque and a torque correction method of the torque wrench.
2. Description of the Related Art
A conventional torque wrench is settable in torque value. When the application force of the wrench reaches a set torque value, an alert effect is provided. The mechanical torque wrench has a trip mechanism. An elastic member abuts against the trip mechanism. The wrench further has an adjustment mechanism for changing the elastic force applied by the elastic member to the trip mechanism. The handle of the wrench is formed with a window with scales for indicating the set torque value of the wrench. In use, the wrench is forced to a bolt or a nut. When the application force of the wrench exceeds the set torque value, the trip mechanism trips to shock the wrench and emit a sound to immediately alert a user that the application force of the wrench has reached the set value.
After a long period of use, the trip mechanism of the wrench will be apparently worn. In this case, the set torque value of the wrench is not the true trip torque value of the wrench. That is, there is an error between the set torque value and the true trip torque value. For example, the set torque value of the wrench is 2 N·m, while the true trip torque value of the wrench is only 1.6 N·m. In this case, actually, the bolt or the nut is not tightened by a necessary torque. This will threaten the security of mechanical equipment or a building.
In case of error of the torque value of the mechanical torque wrench, it is necessary for a user to send the wrench back to the manufacturer or the retailer to replace the parts or correct the torque value. The user himself/herself cannot correct the torque value.